Cummins Inc. and Cummins Westport Inc. announced that the ISX12N+Endurant HD N powertrain from its Integrated power portfolio is now available for heavy-duty customers, delivering a fully integrated natural gas powertrain. The combination of the ISX12N near zero natural gas engine and the Endurant HD N 12-speed automated transmission from Eaton Cummins Automated Transmission Technologies is well suited for heavy-duty regional haul fleets looking to lower emissions and improve their sustainability profile.

When paired with the Endurant HD N automated transmission, the 6-cylinder ISX12N natural gas engine (earlier post) is available with a rating of 400 horsepower and 1,450 lb-ft (1,966 N·m) torque and can operate with 100% compressed natural gas (CNG), liquid natural gas (LNG) or renewable natural gas (RNG).

This reduces smog-forming NO_x emissions by 90% (to 0.02 g/bhp-hr) compared to the current Environmental Protection Agency (EPA) standard. When operated using RNG, the system is credited with a neutral to negative carbon index, resulting in net greenhouse gas (GHG) emissions at or below zero.

The new Endurant HD N automated transmission was optimized for integration with the ISX12N natural gas engine and features new software functionality and calibrations, and a new diaphragm spring clutch designed to meet the load requirements of the natural gas engine while protecting the engine for optimal performance.

The integration between the engine and transmission results in improved launch performance, improved low-speed maneuverability and smoother shifts when compared to previous natural gas engines and automated manual transmission combinations.